SmartPLS 3 allows you to treat missing values. The currently available options are mean value replacement, casewise deletion, and pairwise deletion. For more information, see the chapter on mediation in Hair et al. (2017).
- Hair, J. F., Hult, G. T. M., Ringle, C. M., and Sarstedt, M. (2017). A Primer on Partial Least Squares Structural Equation Modeling (PLS-SEM), 2^nd^ Ed., Sage: Thousand Oaks.